Frequency and waves

Question

WEGT( Hank-FM) operates at a radio frequency of 99.9MHz

a) what is the wavelength of this radiation (hint:1MHz= 10^6Hz)

b) What is the energy of the radio frequency in the problem above in kJ?

Answer 1

Hz = s^-1 = 1/sec

99.9 MHz x 10⁶ Hz/MHz = 99.9x10⁶ Hz = 9.99x10⁷ Hz = 9.99x10⁷ s^-1 = frequency = f

c = λf where c is the speed of light = 3x10⁸ m/sec and λ = wavelength = ?

λ = c/f = 3x10⁸ m/sec / 9.99x10⁷ sec^-1

λ = 3.00 m

E = hf where E = enegy = ?; h = Planck's constant = 6.626x10^-34 J-s; f = frequency = 9.99x10⁷ s^-1

E = (6.626x10^-34 J-s)(9.99x10⁷ s^-1)

E = 6.62x10^-26 J